Tower base assembly for a wind turbine

ABSTRACT

A pre-assembled tower base assembly for a wind turbine configured for transportation to a wind turbine site is disclosed. The tower base assembly includes a tubular side wall defining an internal volume, a first flange portion at a first end of the tubular side wall, a second flange portion at a second end opposite the first end, and a down-tower electrical assembly installed within the internal volume of the tubular side wall. The first flange portion is configured to couple to a foundation. The second flange portion is configured to couple to a tower section. Further, the first and second flanges define a maximum longitudinal extension therebetween. The maximum longitudinal extension is a maximum height permitted for rail or truck transport. As such, the tower base assembly is configured for transportation in an upright position to a wind turbine site with the down-tower electrical assembly pre-assembled within the internal volume.

FIELD OF THE INVENTION

The subject matter disclosed herein relates generally to wind turbines, and more particularly to a tower base assembly for a wind turbine.

BACKGROUND OF THE INVENTION

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture kinetic energy of wind using known airfoil principles. The rotor blades transmit the kinetic energy in the form of rotational energy so as to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.

As the sizes of wind turbines generally increase, the towers of the wind turbines may be modified to accommodate these increases. Such increases in tower size may require constructing the tower in segments and assembling the tower on-site. For example, an 80-meter tower may include three tower sections of varying diameter and thickness. Conventional base tower sections typically have a 4.3-meter maximum diameter and are about 10 to 20 meters long. The space envelope for transport by truck is about 4.3 meters (e.g. to comply with the maximum headroom of bridges), thus allowing a tubular section of approximately that diameter to fit within the space envelope. The space envelope for transport by rail is up to about 3.4 meters to about 4 meters on a side, thus allowing a tubular section of up to that approximate that diameter to fit within the space envelope. Present base sections, therefore, typically exceed the rail envelope and are shipped by truck. As such, the diameter of the base section has to be sized to fit within the space envelope and is transported in a horizontal position (i.e. the longitudinal length of the base section is parallel with the truck bed).

Further, down-tower electrical components, platforms, and other internal fixtures must be installed on-site to avoid disassembly during horizontal transportation of the tower base assembly, further increasing installation and maintenance costs. As such, conventional installation methods employ installing down-tower electrical components on a tower foundation and then using a large crane to lift and lower the base section around the down-tower electrical components.

Accordingly, an improved tower base assembly for a wind turbine would be desired. For example, a tower base assembly for a wind turbine that decreases transportation costs, while also decreasing installation and maintenance costs and time would be advantageous.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one aspect, a pre-assembled tower base assembly for a wind turbine configured for transportation to a wind turbine site is disclosed. The pre-assembled tower base assembly includes a tubular side wall defining an internal volume, a first flange portion at a first end of the tubular side wall; and a second flange portion at a second end of the tubular side wall opposite to the first end. The first flange portion is configured to couple to a tower foundation. The second flange portion is configured to couple to an adjacent tower section. The first and second flanges define a maximum longitudinal extension therebetween, the maximum longitudinal extension being a maximum height permitted for rail or truck transport. A down-tower electrical assembly is installed within the internal volume of the tubular side wall. Accordingly, the pre-assembled tower base assembly is delivered to a wind turbine site with the down-tower electrical assembly already installed and does not require large, costly cranes for installation.

In a further aspect, another embodiment of a pre-assembled tower base assembly for a wind turbine configured for transportation to a wind turbine site is disclosed. The pre-assembled tower base assembly includes a tubular side wall including a plurality of annular segments, at least one platform assembly, and a down-tower electrical assembly. Each annular segment is coupled to another annular segment at a seam, wherein the coupled annular segments define a maximum longitudinal extension, a maximum lateral extension, and an internal volume. The maximum longitudinal extension corresponds to a maximum height permitted for rail or truck transport. The at least one platform assembly is installed within the internal volume of the tubular side wall. Additionally, the down-tower electrical assembly is installed atop the platform assembly and within the internal volume.

In yet another aspect, a method for transporting a pre-assembled tower base assembly of a wind turbine to a wind turbine site is disclosed. The method includes a step of providing a tower base assembly defining a maximum longitudinal extension, a maximum lateral extension, and an internal volume. The maximum longitudinal extension corresponds to a maximum height permitted for rail or truck transport. The method further includes installing a down-tower electrical assembly within the internal volume of the tower base assembly. After installing the down-tower electrical assembly, the method also includes transporting the tower base assembly to a wind turbine site.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 illustrates a perspective view of a wind turbine according to one embodiment of the present disclosure;

FIG. 2 illustrates a cross-sectional view of a tower base assembly according to one embodiment of the present disclosure;

FIG. 3 illustrates a detailed view of one portion of the embodiment of FIG. 2;

FIG. 4 illustrates another detailed view of one portion of the embodiment of FIG. 2;

FIG. 5 illustrates a perspective view of the tower base assembly according to another embodiment of the present disclosure;

FIG. 6 illustrates a cross-sectional view of a pre-assembled tower base assembly installed at a wind turbine site according to one embodiment of the present disclosure;

FIG. 7 illustrates a perspective view of a plurality of tower base assemblies being transported by truck according to one embodiment of the present disclosure; and,

FIG. 8 illustrates a flow diagram of a method for transporting a pre-assembled tower base assembly to a wind turbine site according to one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

Generally, the present disclosure is directed to a pre-assembled tower base assembly for a wind turbine, wherein the tower base assembly and an installed down-tower electrical assembly may be shipped together as one unit. For example, the tower base assembly may be shipped in a vertical or upright position with the down-tower electrical assembly pre-assembled within the tower base assembly before the tower base assembly arrives at a wind turbine site. More specifically, all necessary fixtures, appurtenances, and platforms may be included inside the tower base assembly to properly secure the down-tower electrical assembly during transportation. As such, the tower base assembly is delivered to a wind turbine site in a ready-to-use or operational configuration. Such a configuration reduces transportation costs and eliminates the need for large, costly cranes once the tower base assembly arrives on site.

Referring to the drawings, FIG. 1 illustrates a perspective view of one embodiment of a wind turbine 10. As shown, the wind turbine 10 includes a tower 12 extending from a support surface 14, a nacelle 16 mounted on the tower 12, and a rotor 18 coupled to the nacelle 16. The rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 coupled to and extending outwardly from the hub 20. For example, in the illustrated embodiment, the rotor 18 includes three rotor blades 22. However, in an alternative embodiment, the rotor 18 may include more or less than three rotor blades 22. Each rotor blade 22 may be spaced about the hub 20 to facilitate rotating the rotor 18 to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy. For instance, the hub 20 may be rotatably coupled to the nacelle 16, which encloses an electric generator (not shown) to permit electrical energy to be produced.

As further shown in FIG. 1, the tower 12 may be formed from a plurality of tower sections 14 stacked atop a tower base assembly 30. Further, the tower base assembly 30 may be a connection means for attaching the lowest tower section 14 to the foundation 15. As such, the tower base assembly 30 may form the base of the tower 12 and may be disposed adjacent and coupled to the lowest tower section 14 to at least partially form the tower 12.

In various embodiments, the tower base assembly 30 and the tower sections 14 may be formed from a suitable metal or metal alloy, such as carbon steel. Alternatively, however, the tower base assembly 30 and the tower sections 14 may be formed from any suitable materials, such as, for example, various suitable composite materials. Additionally, the tower base assembly 30 and the tower sections 14 generally have a cylindrical shape. However, it should be understood that the tower base assembly 30 and the tower sections 14 may have any other desired shape and that the outer shape of the tower base assembly 30 is adjusted to the cross-section of the tower 12. For example, the tower base assembly 30 may have a square or rectangular shape.

Referring now to FIGS. 2 through 7, various embodiments of the tower base assembly 30 according to the present disclosure are illustrated. As shown specifically in FIG. 2, the tower base assembly 30 may include a generally tubular side wall 28, one or more flanges at respective ends of the tubular side wall 28, and a platform assembly 37. In still additional embodiments, the tower base assembly 30 may include only one flange, or may include a plurality of flanges. Each of the flanges may be configured to couple the tower base assembly 30 to an adjacent tower section 14 or to a foundation 15. For example, in one embodiment, the tower base assembly 30 may include a first flange portion 24 and second flange portion 26. The first flange portion 24 may extend generally perpendicular to a first end 32 of the tubular side wall 28. Similarly, the second flange portion 26 may extend generally perpendicular to a second end 34 of the tubular side wall 28.

Referring now to FIGS. 3 and 4, the first and second flange portions 24, 26 of the tower base assembly 30 are illustrated in more detail. As shown, the first flange portion 24 has a maximum lateral extension D1. In the case of the first flange portion 24 being circular and ring-shaped, the maximum lateral extension D1 is equal to the outer diameter of the first flange portion 24. However, it should be understood that the concept of a maximum lateral extension is not confined to a cylindrical shape but can be applied also to other cross-sectional shapes of the tower base assembly 30. For example, for a square or rectangular cross-section the maximum lateral extension is given by the diagonals of the square or rectangle.

In one embodiment, as illustrated in FIG. 4, the tubular side wall 28 may be located about midway of the first flange portion 24, thus dividing the first flange portion 24 into an outer portion 44 extending to the outside of the tubular side wall 28 and an inner portion 42 extending to the inside of the tubular side wall 28. Accordingly, the outer and inner portions 44, 42 and the lower part of the tubular side wall 28 may form a T-shaped flange 60.

Referring now to FIG. 3, the second flange portion 26 is located at the opposite or second end 34 of the tubular side wall 28. In the illustrated embodiment, the second flange portion 26 extends inwardly of the tubular side wall 28 so that the second flange portion 26 and the second end 34 of the tubular side wall 28 form an L-shaped flange 62. Thus, the vertical cross-sectional shape of the tower base assembly 30 according to one embodiment can be described as a T-shaped flange 60 being connected to an L-shaped flange 62. However, it should be understood that the second flange portion 26 may also have an outwardly extending portion so that the second flange portion 26 also forms a T-flange.

In further embodiments, the first flange portion 24 may include first through-holes 50, 52 spaced generally circumferentially about the first flange 24. The first through-holes 50, 52 are grouped into outer through-holes 50 located within the outer portion 44 of the first flange portion 24 and inner through-holes 52 located within the inner portion 32 of the first flange portion 24. Second through-holes 54 are similarly formed within the second flange portion 26 and spaced generally circumferentially about the second flange portion 26.

Referring to FIG. 6, the first and second through-holes 50, 52, 54 may be configured to accept a mechanical fastener 58, such as a nut and bolt combination, a rivet, a screw, or any other suitable mechanical fastener 58 therethrough. To couple the tower base assembly 30 to an adjacent tower section 14, the second flange portion 26 may be mated with an adjacent flange 17 of the adjacent tower section 14 such that the through-holes of the mating flanges align. Similarly, to couple the tower base assembly 30 to the foundation 15, the first flange portion 24 may be mated with the foundation 15 by the mechanical fasteners 58. Additionally, the flange portions 24, 26 may be configured according to any suitable configuration known in the art.

Referring back to FIG. 2, the tower base assembly 30 may have a maximum longitudinal extension H, which may also be called the height of the tower base assembly 30. Further, as mentioned, the tower base assembly 30 may have a maximum lateral extension D1, which may also be called the width or diameter of the tower base assembly 30. According to one embodiment, the ratio of the maximum longitudinal extension H and the maximum lateral extension D1 is approximately 1, more specifically in the range of 0.8 to 1. In another embodiment, a ratio of the maximum longitudinal extension and the maximum lateral extension of the tower base assembly may be greater than or equal to 1. Further, in another embodiment, a ratio of a minimum longitudinal extension and a minimum lateral extension of the tower base assembly may be less than or equal to 1.

In other words, the tower base assembly 30 is about as wide as it is high. For example, in one embodiment, the width D1 of the tower base assembly 30 may be in the range of about 4000 millimeters (mm) to 5000 mm and the height H may be in the range of about 3500 mm to about 4500 resulting in an aspect ratio, i.e. height-to-diameter ratio, of about 0.8 to about 1.0. In one embodiment, the height H of the tower base assembly 30 is smaller than or equal to 4.3 meters (m) (i.e. corresponding to standard transportation limits), more specifically from about 3300 mm to 4300 mm, even more specifically, 3800 mm to 4300 mm. As such, the tower base assembly 30 may be transported in an upright or vertical configuration without restriction since it does not exceed the maximum headroom of bridges (i.e. the transportation height limit).

Though the height H is designed such that it may be transported in an upright position, the height H is also tall enough to house the down-tower electrical assembly 38 in an operational configuration. As used herein, the term “operational configuration” is defined generally as a ready-to-use configuration. Accordingly, once the pre-assembled tower base assembly 30 is delivered at the wind turbine site, the only remaining installation step is to secure the tower base assembly 30 to the foundation 15. Furthermore, the weight of the tower base assembly 30 is typically smaller than or equal to 20,000 kg, more specifically 10,000 kg, even more specifically, 5000 kg. Such a configuration eliminates the need for a large, costly crane to lift the tower base assembly 30 around the down-tower electrical assembly 38 when the pre-assembled tower base assembly 30 arrives on site. Accordingly, the tower base assembly 30 is relatively small and can be handled even by a single small mobile crane. Since the tower base assembly 30 can be handled by a single small crane, the costs are considerably reduced compared to conventional construction necessitating two larger cranes.

Referring still to FIGS. 2 and 6, the tubular side wall 28 may have an exterior portion 46 and an interior portion 48. The exterior portion 46 and interior portion 48 may further generally define a thickness T of the tower base assembly 30 therebetween. Further, the tower base assembly 30 may define an internal volume 36 configured to house a down-tower electrical assembly 64 therein. In one embodiment, the internal volume 36 may be defined as the space defined between the first and second flanges 24, 26. The internal volume 36 is designed such that a down-tower electrical assembly 38 may fit therein.

The down-tower electrical assembly 38 may include a variety of electrical components associated with wind turbine operation. For example, in one embodiment, the down-tower electrical assembly 38 may include any one of or combination of the following components: one or more electrical cabinets 39, electrical equipment, such as a transformer, a plurality of circuits, fixtures, appurtenances, or a control system. In a further embodiment, the electrical cabinets 39, for example, may be the distribution cabinets for auxiliaries of the entire wind turbine 10 and may provide access for operation and maintenance work. Additionally, the electrical assembly 38 may allow for full control and operation of the wind turbine 10, as well as a means for providing information on all operated and measured signals.

As mentioned, the electrical assembly 38 may be mounted on a platform assembly 37 as shown in FIGS. 2 and 6. In one embodiment, the platform assembly 37 may sit on the tower foundation 15 (FIG. 2). Further, the platform assembly 37 may be integral with the first flange portion 24 or may a separate component installed within the tower base assembly 30. Alternatively, the platform assembly 37 may be mounted on an inner surface 48 of the tubular side wall 28 (FIG. 6). More specifically, in one embodiment, the platform assembly 37 may rest approximately 1 meter (m) above the ground and the electrical cabinets 39 may be approximately 2.5 m tall. As such, the total combined height of the platform assembly 37 and the electrical assembly 38 is less than the longitudinal extension H of the tower base assembly 30 such that the tower base assembly 30 may be transported in an upright position without restrictions.

It should be understood that the platform assembly 37 may be designed with any suitable dimensions so as to fit within the tower base assembly 30. For example, as shown in FIG. 2, the platform assembly 37 may be designed to fit within the first flange portion 24. In addition, the platform assembly 37 may be designed to fit within the inner surface 48 of the tubular side wall 28. Further, the platform assembly 37 may be fabricated using any suitable materials so as to support the down-tower electrical assembly 38.

Referring now to FIG. 5, the tubular side wall 28 of the tower base assembly 30 may, in some embodiments, include a plurality of annular segments 40. Each of the annular segments 40 may be a generally cylindrical portion of the tower base assembly 30, and may define a portion of the longitudinal extension H of the tower base assembly 30 as well as the thickness 28 of the tower base assembly 30. Each of the plurality of annular segments 40 may be disposed adjacent and coupled to another one of the plurality of annular segments 40 to at least partially form the tubular side wall 28. Further, the annular segments 40 may be coupled together by, for example, welding the annular segments 40 together at intersections 41 between the adjacent annular segments 40. It should be understood, however, that the present disclosure is not limited to welding, and that any suitable fastening device or method may be utilized to couple the annular segments 40 together.

Additionally, any number of annular segments 40 may be utilized to achieve the desired longitudinal extension H. In one embodiment, as shown in FIG. 5, two annular segments 40 are welded together at a weld seam 41. As such, each annular segment 40 may have a height of from about 2 m to about 2.2 m to achieve the desired longitudinal maximum extension H of about 4.3 m. In still further embodiments, the annular segments 40 may have different heights, for example, such as one segment having a height of about 1.8 m and another segment having a height of about 2.5 m. It should be understood that the tower base assembly 30 may have any number of annular segments 40, such as one, two, three, or more. Further, each segment 40 may have any suitable height, and the examples provided herein are for illustrative purposes only and are not meant to be limiting. Moreover, the cross-sectional area of the tower base assembly 30, and thus the annular segments 40, may remain constant or may taper through the height H of the tower base assembly 30 or portions thereof. For example, in some embodiments, the cross-sectional area of each of the annular segments 40 and tower base assembly 30 may decrease through the height H or a portion thereof.

Still referring to FIG. 5, the tower base assembly 30 may also include an access opening 38 to provide operators with access to the down-tower electrical assembly 38 as well as other areas within the wind turbine that may need repair and/or maintenance. Further, one or more ladders or platform assemblies 37 may be provided within the tower base assembly 30 to provide access to higher portions of the wind turbine 10. In further embodiments, the access opening 38 may include a door or covering or may remain open.

Referring now to FIG. 7, a plurality of tower base assemblies 30 are illustrated being transported atop a flat-bed truck. It should be understood that the tower base assemblies 30 may also be transported or shipped using any suitable means in the art, such as a rail car or similar. As shown, each of the tower base assemblies 30 are illustrated in an upright or vertical position. As mentioned, such a transportation configuration is possible due to the maximum longitudinal extension (i.e. the height of each tower base assembly 30) remaining less than transportation height limits of most global markets without restriction. Additionally, as shown, each of the tower base assemblies 30 includes the down-tower electrical assembly 38 already installed within the internal volume 36 of the tower base assembly 30. As such, when the pre-assembled tower base assemblies 30 arrive at a wind turbine site, the tower base assemblies 30 are quickly and easily installed on the tower foundation 15. Accordingly, the tower base assembly 30 as described herein decreases transportation costs, while also decreasing installation and maintenance costs and time.

Referring now to FIG. 8, the present disclosure is further directed to a method 100 for transporting a pre-assembled tower base assembly of a wind turbine, to a wind turbine site. The method may include, for example, the step 102 of providing a tower base assembly 30. Further, the tower base assembly 30 may define a maximum longitudinal extension, a maximum lateral extension, and an internal volume, the maximum longitudinal extension being a maximum height permitted for rail or truck transport. In a further embodiment, the method 100 may also include joining a plurality of annular segments to form the tower base assembly.

The method 100 may further include the step 104 of installing a down-tower electrical assembly 38 within the internal volume 36 of the tower base assembly 30. In another embodiment, the step 104 of installing the down-tower electrical assembly 38 may further include securing one or more components associated with the down-tower electrical assembly 38 within the internal volume 36 of the tower base assembly 30. As mentioned, the one or more components associated with the down-tower electrical assembly 38 may include any one of or combination of the following components: one or more electrical cabinets 39 and/or electrical equipment, such as a transformer, a plurality of circuits, fixtures, appurtenances, platforms, or a control system. Additionally, the method 100 may further include the step 106 of, after installing the down-tower electrical assembly, transporting the tower base assembly 30 to a wind turbine site.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 

1. A pre-assembled tower base assembly for a wind turbine configured for transportation to a wind turbine site in an upright position, the tower base assembly comprising: a tubular side wall defining an internal volume; a first flange portion at a first end of the tubular side wall, the first flange portion configured to couple to a tower foundation; a second flange portion at a second end of the tubular side wall opposite to the first end, the second flange portion configured to couple to an adjacent tower section, wherein the first and second flange portions define a maximum longitudinal extension therebetween, the maximum longitudinal extension is greater than 3.8 meters and less than about 4.3 meters; at least one platform assembly installed within the internal volume; and, a down-tower electrical assembly installed within the internal volume of the tubular side wall atop the at least one platform assembly such that the pre-assembled tower base assembly can be transported in the upright position with the down-tower electrical assembly configured therein.
 2. (canceled)
 3. The tower base assembly of claim 1, wherein the tubular side wall comprises a maximum lateral extension, wherein the maximum lateral extension ranges from about 4.3 meters to about 4.6 meters.
 4. The tower base assembly of claim 3, wherein the maximum lateral extension corresponds to a maximum diameter of the tower base assembly.
 5. The tower base assembly of claim 1, wherein the tower base assembly has a weight equal to or less than 20,000 kilograms.
 6. The tower base assembly of claim 1, wherein the down-tower electrical assembly comprises any one of or combination of the following components: one or more electrical cabinets, a transformer, a plurality of circuits, one or more fixtures, one or more appurtenances, or a control system.
 7. (canceled)
 8. The tower base assembly of claim 1, wherein the platform assembly is integral with the first flange portion.
 9. The tower base assembly of claim 1, wherein the platform assembly is installed between the first flange portion and the second flange portion.
 10. The tower base assembly of claim 1, wherein the tubular side wall comprises a plurality of annular segments, each annular segment coupled to another annular segment to form the tubular side wall, wherein each annular segment is welded together at a weld seam.
 11. The tower base assembly of claim 1, wherein the first flange portion extends perpendicularly to the tubular side wall, and wherein the second flange portion extends perpendicularly to the tubular side wall.
 12. The tower base assembly of claim 11, wherein the first flange portion has an outer portion extending outside of the tubular side wall and an inner portion extending inside of the tubular side wall, wherein the first flange portion and the tubular side wall form a T-shaped flange, wherein the second flange portion extends inwardly from the tubular side wall, and wherein the second flange portion and the tubular side wall form an L-shaped flange.
 13. The tower base assembly of claim 1, further comprising an access opening within the tubular side wall so as to provide access to the internal volume.
 14. A pre-assembled tower base assembly for a wind turbine configured for transportation to a wind turbine site in an upright position, the tower base assembly comprising: a tubular side wall comprising a plurality of annular segments, wherein each annular segment is coupled to another annular segment at a seam, wherein, the coupled annular segments define a maximum longitudinal extension, a maximum lateral extension, and an internal volume, the maximum longitudinal extension being less than about 4.3 meters; at least one platform assembly installed within the internal volume; and, a down-tower electrical assembly installed atop the platform assembly within the internal volume such that the pre-assembled tower base assembly can be transported in the upright position with the down-tower electrical assembly configured therein.
 15. The tower base assembly of claim 14, wherein the maximum longitudinal extension is greater than about 3.8 meters, and the maximum lateral extension ranges from about 4.3 meters to about 4.6 meters.
 16. The tower base assembly of claim 14, wherein the tower base assembly has a weight equal to or less than 20,000 kilograms.
 17. The tower base assembly of claim 14, wherein the down-tower electrical assembly comprises any one of or combination of the following components: one or more electrical cabinets, a transformer, a plurality of circuits, one or more fixtures, one or more appurtenances, or a control system.
 18. A method for transporting a pre-assembled tower base assembly of a wind turbine, the method comprising: providing a tower base assembly defining a maximum longitudinal extension, a maximum lateral extension, and an internal volume, the maximum longitudinal extension being less than about 4.3 meters; installing at least one platform assembly within the internal volume; installing a down-tower electrical assembly atop the platform assembly within the internal volume of the tower base assembly; and, after installing the down-tower electrical assembly, transporting the tower base assembly to a wind turbine site in an upright position with the down-tower electrical assembly configured therein.
 19. The method of claim 18, further comprising joining a plurality of annular segments together to form the tower base assembly.
 20. The method of claim 18, wherein installing the down-tower electrical assembly further comprises: securing the down-tower electrical assembly within the internal volume of the tower base assembly, wherein the down-tower electrical assembly comprises any one of or combination of the following components: one or more electrical cabinets, a transformer, a plurality of circuits, one or more fixtures, one or more appurtenances, or a control system. 